An advanced 2-D spectrum for high-resolution and MEO spaceborne SAR

In this paper, an advanced range equation is presented for high-resolution and medium-earth-orbit (MEO) synthetic aperture radar (SAR). Besides an additional linear component, this new equation has a similar formalism to conventional hyperbolic range equation (CHRE), so is called the advanced hyperbolic range equation (AHRE). Incorporating with this additional linear coefficient and the other two parameters, the cubic Taylor series expansion of AHRE has exactly the same value as which of the actual range history. Furthermore, a two-dimensional (2-D) spectrum based on AHRE is derived, which is useful for developing efficient SAR algorithms. Simulations validate AHRE and show its advantages in high-resolution and MEO spaceborne SAR cases.